Improvement in cupola furnaces for melting iron



J. D. MARSHBANK.

Improvement in Cupola-Furnaces for Melting Iron.

N0.129,151. n edJuly16,1872.

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UNITED STATES PATENT QFFICE.

JOHN D. MARSHBANK, OF HARRISBURG, PENNSYLVANIA, ASSIGNOR OF TWO-THIRDS OF HIS RIGHT TO WILLIAM A. MIDDLETON AND GEORGE F. WEAVER, JR, OF SAME PLACE.

IMPROVEMENT IN CUPOLA FURNACES FOR MELTING IRON.

Specification forming part of Letters Patent No. 129,151, dated J nly 16, 1872.

To all whom it may concern:

Be it known that I, JOHN D. MARSHBANK, of Harrisburg, in the county of Dauphin and in the State of Pennsylvania, have invented certain new and useful Improvements in Gupola for Melting Iron and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing and to the letters of reference marked thereon making a part of this specification.

The nature of my invention consists in the construction and arrangement of the interior lining of cupolas for foundry purposes, as will be hereinafter more fully set forth.

In .rrder to enable others skilled in the art to which my invention appertains to make and use the; same, I will now proceed to describe its corstruction and operation, referring to the annexed drawing, in which- Figure l is a front View, Fig. 2, a longitudinal vertical section, and Fig. 3 a plan view, of a cupola for foundries, showing the interior lining; and Fig. 4 is a horizontal section of the same taken through the linewzv of 'Fig. 2.

A represents the outer shell of the cupola, and B the interior lining, which latter is made in oval oblong form, as shown, which form is carried up or continued to just below the charge-door G. This is done for the purpose of shortening the distance from the discharge of the tnyeres to the center, requiring less pressure of the blast to carry it to that point than is required in other forms of cupolas. D D represent the tuyeres, which are arranged on opposite sides of the cupola so as to alternate; or, in other words, the blast from each tuyere comes directly opposite the space between two tuyeres on the other side. By this arrangement of the tuyeres the blasts from them do not interfere with each other; but a limited pressure will carry it to the center of the charge on the coal-bed, thereby obtaining a uniform combustion of the fuel and preventing the formation of a central core, which, in heavy heats, causes the rolling of the charges over on the tuyeres and clogging of the same. Above the tuyeres the oval oblong lining B is thrown back, making it egg-shape, which accomplishes the following important results:

First, it increases the area of melting surface at the best melting point over the tuyeres and where the blast is most efficient; second, by

this form of lining it prevents the blast from cutting it away, as is the case where the lining is straight; and third, it prevents the possibility of the stock lodging or bridging, which is often a source of annoyance and expense,

pose of preventing the escape of the gases and a too rapid ignition of the coal between the charges before it reaches the real melting point above the tuyeres, thereby economizing fuel. E E represent the openings to the tuyeres and to the inside of the air-chamber G, constructed in such a manner that any obstructions to the tuyeres can be readily removed at any time.

By this construction of the cupola I claim that a given quantity of iron can be melted in a shorter space of time, with a less quantity of fuel, less pressure of blast, and give a softer iron than by any other form of cupola of which I have any knowledge.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The interior lining B of a cupola for foundry furnaces, when made in oval oblong form, thrown back in egg-shape above the tuyeres, and contracted at the top just below the charge-door, substantially as and for the purposes herein set forth.

2. In combination with the interior lining B, constructed as described, I claim tuyeres D D, arranged on opposite sides of the cupol'a so as to alternate, substantially as and for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 8th day of March, 1872.

JOHN D. MARSHBANK. Witnesses:

HERVEY E. SMITH, A. 0. SMITH. 

